This invention relates to a process for forming a thin metal hydride film and is directed more particularly to a method of forming a titanium bydrogen isotopic film.
In general, titanium hydrogen isotopic films made with deuterium or tritium are useful as superior neutron generator targets, corrosive resistant coatings, hydrogen diffusion barriers or for hydrogen storage. Titanium films that are partly loaded with deuterium or tritium are in general used as neutron generator targets. However, such films are substantially TiD.sub.1 or TiT.sub.1 compounds and consist of a two-phase mixture of titanium metal and titanium dideuteride or titanium tritide. Thus, the films are not stoichiometric.
Powders compounded of TiH.sub.2 and TiD.sub.2 have been formed in the past but have not been successfully used to provide continuous films. The titanium hydrogen isotopic films of the prior art have been porous and brittle and have had poor electrical and thermal conductivity. These factors are generally objectionable and are particularly objectionable for neutron targets.
Metal hydride films to be useful as corrosion resistant coatings or hydrogen diffusion barriers must be free of occlusions, cracks orother discontinuities. A hydrogen diffusion barrier, by way of example, may comprise a metal hydride film on the inner surface of a metal tank. Such a film prevents any isotopes of hydrogen present in the tank from embrittling the metal which may cause destruction of the tank.